The field of illumination of an object in an imaging system, and in particular imaging of in vivo biological tissue.
The problem of imaging biological tissue and classification of the resulting images is treated in great detail in U.S. Pat. Nos. 6,081,612 and 6,208,749, assigned to the assignee of the present invention. In order to reach the acceptable levels of accuracy in the diagnosis, for example, of melanoma, all aspects of the imaging system must be optimized. In particular, the light source used to illuminate the region of interest of the tissue must be matched particularly to the lens system and to the recording device recording the image. Prior art systems use a ring illuminator to give uniform illumination for this purpose, but the prior art system is slow and heavy, with inefficient generation of light and inefficient use of the light which is generated. In particular, prior art systems for multispectral imaging are particularly wasteful of light, as they use a rotating filter wheel and only use a small portion at a time of the spectrum of the ring light.
Prior art systems using flexible optical fiber technology to deliver light to an object require trained personnel to adjust the light source to give the required illumination. Prior art light emitting diode (LED) systems do not have sufficient power to illuminate a large area uniformly, and the LED""s do not have adequate consistency from diode to diode in that the light emitted from the diode will not consistently have a well enough defined relationship between the pattern of the light produced and the body of the diode to allow the diode to be xe2x80x9clined upxe2x80x9d using the physical body of the diode.
It is an object of the invention to produce an illumination system which will illuminate a body with sufficient uniformity for exacting imaging requirements. It is an object of the invention to produce an illumination system which will illuminate a body using high efficiency in the conversion of electrical energy to spectrally resolved light energy for the purpose of imaging. It is an object of the invention to produce an illumination system which will produce uniform illumination of biological tissue light over a large area. It is an object of the invention to produce an illumination system which will produce uniform illumination of biological tissue with light over a large area, where the light frequency is changed at will.
The present invention is a system, apparatus and method to produce and use a large plurality of light sources to illuminate an object with sufficient uniformity for critical imaging applications. Each of the plurality of light sources is held in adjustable relationship with a base, and the light source and the base are relatively oriented so that the illumination pattern produced by the light source bears the correct relationship with respect to the base. Once the correct relationship has been achieved, the light source is rigidly affixed to the base and the next light source is oriented and affixed.